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—Presented here is an approach to analyzing the effect of imperfect channel estimation on adaptive modulation. The sensitivity of the main performance parameters to short-term and long-term estimation error sources is summarized in a set of new formulas that are either closed-form expressions or simple to compute numerically.
—In this letter, the utilization of a finite number of power levels per constellation in adaptive QAM schemes for flat fading channels is analyzed. Assuming a maximum target BER, the optimum switching thresholds in order to maximize the spectral efficiency are found for Rayleigh fading. Both analysis and simulation results show that a small number of power(More)
This paper presents a new connection between the generalized Marcum-Q function and the confluent hypergeometric function of two variables, Φ 3. This result is then applied to the closed-form characterization of the bivariate Nakagami-m distribution and of the distribution of the minimum eigenvalue of correlated non-central Wishart matrices, both important(More)
Important throughput improvements can be obtained in multiple-input multiple-output (MIMO) fading channels by merging beamforming at the transmitter and maximal ratio combining (MRC) at the receiver. However, accurate channel state information (CSI) is critical to achieve these performance gains. In this paper, we analyze the impact of imperfect CSI on the(More)
In this work multiplexing of variable-rate sources over shared generic multiple fading channels is addressed. In general, the performance of existing multiplexing algorithms has been compared in very specific environments, making it difficult to draw general conclusions. In this article we propose a generic variable-rate multiuser and multichannel system(More)
— Adaptive modulation schemes for fading channels are usually required to fulfill certain long-term average BER targets. However, for simplicity and mathematical tractability, these schemes are often designed by fixing the short-term instantaneous BER to the target value. In this paper, the analysis and design of variable-rate variable-power QAM schemes(More)
—This paper provides new results for a family of incomplete Lipschitz–Hankel integrals (ILHIs) which also lead to the evaluation of certain integrals involving the generalized Marcum Q function. These mathematical results are then applied to analyze the bit error rate (BER) of adaptive modulation over multiple-input–multiple-output (MIMO) fading channels(More)
— Adaptive modulation schemes for fading channels are usually required to fulfill certain long-term average BER targets. However, for simplicity and mathematical tractability, these schemes are often designed by fixing the short-term instantaneous BER to the target value. In this paper, the analysis and design of variable-rate variable-power QAM schemes(More)